1. Field of the Invention
The present invention relates to an image pickup apparatus such as a digital camera and a video camera.
2. Description of the Related Art
Image pickup apparatuses provided with an image pickup element such as a CCD sensor or a CMOS sensor include an optical filter such as an infrared cutting filter or an optical low-pass filter disposed closer to an object than a light-receiving surface (image pickup surface) of the image pickup element. Attachment of foreign substances such as dust invading from the outside of the image pickup apparatus and abrasion powder generated at mechanical sliding surfaces inside the image pickup element onto the light-receiving surface of the image pickup element or the optical filter causes the image pickup element to capture images of the foreign substances, which may generate a captured image including the images of the foreign substances.
The attachment of the foreign substances onto the light-receiving surface of the image pickup element and an image pickup element side surface of the optical filter is often prevented by providing a dust-proof structure that surrounds a space between these surfaces. On the other hand, Japanese Patent Laid-Open No. 2007-264096 discloses a dust removing mechanism that vibrates an optical filter by using a piezoelectric element to remove foreign substances attached onto an object side surface (that is, a surface opposite to the image pickup element side surface) of the optical filter.
However, providing such a dust removing mechanism disclosed in Japanese Patent Laid-Open No. 2007-264096 complicates the configuration of the image pickup apparatus and increases the size of the image pickup apparatus.
Moreover, employing the dust removing mechanism for an image pickup apparatus in which an image pickup element unit including the image pickup element and the optical filter is moved in an optical axis direction to perform zooming or the like increases the size of a drive mechanism that moves the image pickup element unit whose weight is increased by addition of the dust removing mechanism.